Answer:
Waterfalls often form in the upper stages of a river where it flows over different bands of rock. It erodes soft rock more quickly than hard rock and this may lead to the creation of a waterfall.
Formation of a waterfall:
▪︎The soft rock erodes more quickly, undercutting the hard rock.
▪︎The hard rock is left overhanging and because it isn’t supported, it eventually collapses.
▪︎The fallen rocks crash into the plunge pool. They swirl around, causing more erosion.
▪︎Over time, this process is repeated and the waterfall moves upstream.
▪︎A steep-sided gorge is formed as the waterfall retreats.
